Résumé Nzega is among the district located in semi-arid areas of Tanzania where drought is a limiting factor for agriculture. In the district farmers are advised to use early maturing maize varieties (EMMV). In contrary the adoption of EMMV in Nzega District is still low. Increase in use of EMMV is possible if factors which influence adoption are addressed. The present study aimed at identifying factors which influence adoption of EMMV. The main objective was to analyze challenges facing efforts to improve maize production through the promotion of adoption of EMMV. The specific objectives were to compare profitability of EMMV and the traditional maize varieties, to identify determinants of adoption of EMMV and to determine factors affecting the level of adoption of EMMV. A total of 150 maize farmers consisting of adopters and non-adopters of EMMV were involved. Multistage random sampling technique was used to select maize farmers from 10 villages. Data were collected through structured questionnaire. Gross margin was used to compare the profitability of EMMV and the traditional maize varieties. Cragg’s double hurdle model was used in determining factors affecting adoption decision and the level of adoption. The results show that the gross margin for EMMV is higher than the traditional maize varieties. Results also show that extension services, education level of the household and size of the farm owned by the farmer were significant in affecting both the adoption decision and the level of adoption. Factors like family labour, family dependency ratio, number livestock units owned by the farmer and distance to the nearest market were significant in explaining adoption decision only. The present study concludes that low adoption of EMMV can be attributed to institutional and socio-economic factors. Therefore the Government should put more effort in improving extension services, markets and provision of input subsidies for maize farmers